Preface

The rapid industrialization of the last two centuries has often caused environmental contamination far beyond the confines of the industrial sector. Further, as the size and scale of industrial activities have increased, a number of dramatic industrial accidents, such as those at Seveso and Bhopal, have heightened public awareness of the potential risks of such activities to the health of the surrounding population and to the environment. Public concern is more acute when the nature and toxicity of the chemicals discharged are uncertain, the extent of environmental contamination is unknown, and the health consequences are poorly understood. Exposure to chemicals may cause new, previously observed diseases or exacerbate diseases of another etiology.

Epidemiology is an important tool for evaluating the health consequences for populations exposed to chemicals as a result of chemical incidents or environmental contamination. Many parallels can be drawn with the use of classical epidemiology in the investigation of infectious diseases. Further, epidemiological methods may be used to evaluate the effectiveness of activities to reduce the health effects of exposure to chemicals.

The participants in the United Nations Conference on Environment and Development, held in Rio de Janeiro in June 1992, noted that gross chemical contamination of the environment with grave damage to human health, genetic material and reproductive outcomes has arisen in recent times in some of the world’s most important industrial areas. They defined an international strategy for the environmentally sound management of chemicals within the principles of sustainable development and improved quality of life for humankind. The participants recognized, however, that both national and international efforts need significant strengthening to carry out this strategy. They identified the promotion of international cooperation in the prevention of and response to chemical accidents as an important aspect of the process.

Over the past 15 years, both the WHO Regional Office for Europe and the International Programme on Chemical Safety (IPCS) (a joint venture of WHO, the International Labour Organisation (ILO) and the United Nations Environment Programme (UNEP)) have taken a number of important initiatives in the prevention of and response to chemical accidents. Planning emergency response systems for chemical accidents¹ was issued in 1981. In 1987, jointly with the International Council of Scientific Unions (ICSU) Scientific Committee on Problems of the Environment (SCOPE), IPCS published Methods for assessing and reducing injury from chemical accidents.² In 1994, IPCS and the WHO European Centre for Environment and Health collaborated with the Organisation for Economic Co-operation and Development (OECD) and UNEP on Health aspects of chemical accidents,³ giving guidance on chemical accident awareness, preparedness and response for health professionals and emergency response personnel. At present, IPCS is developing guidelines on the role of the public health sector in chemical incident preparedness, response and follow-up, directed specifically at public health policy-makers to help them establish the necessary administrative infrastructure and measures. These guidelines do not deal with the technical aspects and the tools involved, but recognize the need for specific publications on these topics, such as epidemiological methods.

¹Planning emergency response systems for chemical accidents. Administrative guidelines. Copenhagen, WHO Regional Office for Europe, 1981 (document).

²Methods for assessing and reducing injury from chemical accidents. Geneva, World Health Organization, 1987.

³Health aspects of chemical accidents. Paris, Organisation for Economic Cooperation and Development, 1994 (OECD Environmental Publication, OECD/GD (94)1).

This publication complements those already cited and is directed specifically at the public health official or epidemiologist who may need to plan or undertake an epidemiological study of populations exposed to chemicals through major accidents or environmental contamination. It is meant to promote awareness of the role of epidemiology among public health professionals managing chemical incidents and to describe some tools for designing and implementing studies, but not to be a detailed technical manual.

After an initial consultation in 1994 and discussion on the need for such a publication at the forum of the European Concerted Action “Air Pollution Epidemiology”, the WHO European Centre for Environment and Health set up the Working Group on Epidemiological Approaches to Assessment of Health Consequences of Accidents and Disasters. At its first meeting in Basle on 12-13 January 1995, the Group examined the epidemiological investigations that had followed a number of well known chemical accidents, to identify the key elements of these investigations as the basis for a guideline document. The Group drew up the outline of the present publication and assigned the sections to be drafted to various experts. The Working Group examined the first draft of the document at a meeting in Bilthoven on 4-5 May 1995. The Editorial Group edited the draft and circulated it for peer review. A summary was presented for discussion at the annual Meeting of the International Society for Environmental Epidemiology in August 1995. As a result of this discussion, and using comments on the draft from the Working Group members and the invited reviewers, the Editorial Group prepared a final version that was reviewed again by the members of the Working Group.

This work was made possible through the financial support of the Government of Switzerland, which is gratefully acknowledged.

I believe that the Working Group has created a good basis for the application of environmental epidemiology to the management of chemical incidents, and that its work will contribute to a reduction of associated health effects.

Kees van der Heijden
Director, Bilthoven Division
WHO European Centre for Environment and Health